The purpose of this project is to provide independent consultation to researchers within the NCI on problems related to biostatistical methodology and cancer control. Current projects include: - in collaboration with the Cancer Prevention Studies Branch, the American Association of Retired Persons (AARP) Observational Cohort Study has entered its third year. During the past year, a cohort of AARP members was created to investigate the relationship between their current dietary intake and their future incidence of cancer of the breast, colon/rectum, and prostate the internal calibration study has been constructed that includes about 2,000 members of the full cohort; and the 24-hour diet recalls and the second food frequency questionnaire (FFQ) were obtained for the subjects of the calibration study. Analysis of the calibration study has begun, which will allow us to evaluate the FFQ measurement errors and to correct the results of the main study for this error. - in collaboration with the Cancer Prevention Studies Branch, we completed research projects on 1) dietary folate intake and colorectal cancer and 2) the effects of dietary fat and fiber intake on androgen and estrogen levels in men. - in collaboration with the Cancer Prevention Studies Branch and the Applied Research Branch, a newly developed FFQ is being evaluated; over 600 participants were enrolled in a study using a daily checklist of selected foods to evaluate the food frequency accuracies of a sample of questionnaire items. - in collaboration with the Prevention and Control Extramural Branch, the Section provides consultation on the analysis and evaluation of the 5 A Day Program -- NCI's campaign to increase fruit and vegetable consumption. - in collaboration with the Applied Research Branch and the Environmental Epidemiology Branch, DCEG, the relationship between selenium status and cervical cancer is being investigated.